The present invention relates to an automatic lamp changer for a slide projector, and more particularly, an automatic lamp changer for use with a slide projector having a modular lamp replacement unit.
Slide projectors have found particular acceptance for use by educators and business people as an excellent means for communicating with audiences. Portable slide projector systems are equipped with synchronized sound and are particularly convenient and versatile to use. Slide projectors generally use a high intensity lamp which directs light through a slide and a lens for projection on a remote screen.
A recognized weak point in slide projectors is in the lamp system. The lamp can fail during a presentation and this means that the projection must be interrupted for a substantial amount of time to allow the hot burned out lamp to cool so that it can be replaced. If a lamp burns out in a display which images are projected by more than one projector onto a single screen, a noticeable blank space will be left on the screen which detracts from the intended visual effect. For unattended operation of slide projectors, it becomes almost imperative to provide automatic lamp changing to prevent loss of the projected image and to eliminate the need for an emergency service call to relamp the projector. Relamping prior to burnout can prove to be a very expensive alternative.
Another problem that plagued conventional projectors, was that the lamp access was only from the bottom of the projector and thus the projector had to be turned upside down to replace the lamp. This required repositioning of the projector after the lamp change, which was particularly inconvenient due to the great deal of time and effort required on the part of the operator to do so.
A new slide projector introduced by Kodak and called the EKTAGRAPHIC III, sought to reduce the aforesaid problems by housing its projection lamp in a module, which is removable from the rear of the projector. The module housing the lamp is accessed by opening an access door at the rear of the projector and pulling the module out. Unless one has a complete replacement module, there is still the disadvantage that the operator must wait until the bulb cools down in order to replace it with a new bulb.
Thus, while the need to turn the projector upside down upon burn-out of the lamp is eliminated, the delays associated with changing the burned out bulb still exists.
One way in which the problem of lamp burn out was overcome in the past, was with the provision of an automatic lamp changer with multiple lamps such as the ones disclosed in U.S. Pat. Nos. 3,914,645 and 4,061,911. However, these units are not compatible with the new Kodak EKTAGRAPHIC III modular projector.